refactor(effects): co-locate effect WGSL shaders with their .h/.cc in src/effects/

Move 13 effect-specific shaders from workspaces/main/shaders/ to src/effects/
so each effect's .h, .cc, and .wgsl are together. Update assets.txt paths in
both main and test workspaces. Update EFFECT_WORKFLOW.md to reflect new location.
Shared/reusable snippets remain in src/shaders/.

handoff(Gemini): shaders moved; src/effects/ now has .h, .cc, and .wgsl per effect.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/effects/particle_compute.wgsl b/src/effects/particle_compute.wgsl
new file mode 100644
index 0000000..2960cc4
--- /dev/null
+++ b/src/effects/particle_compute.wgsl
@@ -0,0 +1,31 @@
+// Particle simulation (compute shader) - V2
+struct Particle {
+    pos: vec4f,
+    vel: vec4f,
+    rot: vec4f,
+    color: vec4f,
+};
+
+#include "sequence_uniforms"
+
+@group(0) @binding(0) var<storage, read_write> particles: array<Particle>;
+@group(0) @binding(1) var<uniform> uniforms: UniformsSequenceParams;
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) id: vec3u) {
+    let i = id.x;
+    if (i >= arrayLength(&particles)) {
+        return;
+    }
+    var p = particles[i];
+    let new_pos = p.pos.xyz + p.vel.xyz * 0.016;
+    p.pos = vec4f(new_pos, p.pos.w);
+    p.vel.y = p.vel.y - 0.01 * (1.0 + uniforms.audio_intensity * 5.0);
+    p.rot.x = p.rot.x + p.rot.y * 0.016;
+    if (p.pos.y < -1.5) {
+        p.pos.y = 1.5;
+        p.pos.x = (f32(i % 100u) / 50.0) - 1.0 + (uniforms.audio_intensity * 0.5);
+        p.vel.y = 0.0;
+    }
+    particles[i] = p;
+}